(A-097) Comparative effectiveness of etelcalcetide versus cinacalcet for the treatment of secondary hyperparathyroidism in patients in haemodialysis: a population-based study in Lazio, Italy

Background: Secondary hyperparathyroidism (SHP) is a meaningful clinical complication commonly present in chronic renal disease, especially in patients in haemodialysis. Pharmacological therapy aims at reducing the level of parathyroid hormone (PTH). Among specific treatments, the long-acting calcimimetic etelcalcetide was authorised in Italy a few years ago based on the results of clinical trials. Still, evidence of efficacy in the real world is scarce.

Objectives: The present study, conducted with funds from the Italian Medicines Agency (Pharmacovigilance call 2012-14), aims to perform a comparative evaluation of SHP control associated with the use of the two calcimimetics etelcalcetide and cinacalcet in patients in chronic haemodialysis in a real-world setting.

Methods: From the Lazio Regional Dialysis and Transplantation Registry, a cohort of new users of cinacalcet and etelcalcetide in the years 2018-2020 was enrolled. Study endpoints were retrieved through an ad hoc survey in regional dialysis centres. Indicators of SHP control were serum levels of PTH, phosphorus and calcium, which were evaluated by comparing the proportions of patients at target and mean blood levels at baseline, 12 and 24 months of observation.

Results: Overall, 652 haemodialytic patients were enrolled, 59% males and a mean age of 64 years. Most patients (500) initiated treatment with etelcalcetide.
In both treatment groups, serum PTH improved over time, both in terms of increased proportions of patients meeting the therapeutic target (etelcalcetide from 37.8 at baseline to 59.3% at 24 months; cinacalcet from 39.5 to 63.3%) and a significant decrease of PTH blood levels (etelcalcetide from 605.2 to 372.9pg/mL; cinacalcet from 577.9 to 285.1pg/mL). Also, serum phosphorus levels showed improvements over time, with an increase in the proportions of patients on target (etelcalcetide from 23.0 to 36.0%; cinacalcet from 19.1 to 26.7%), while mean blood levels decreased in cinacalcet users only. Results for serum calcium levels had less impact, yielding no differences over time for patients at target in cinacalcet users and a decrease in etelcalcetide users, while mean blood levels remained stable.

Conclusions: The present study indicates improvements in SHP control in both treatment groups and differences between treatments are negligible. Along with previous findings of a mortality reduction in patients treated with etelcalcetide with respect to cinacalcet, with a borderline statistical significance, this study confirms the efficacy and safety of etelcalcetide in SHP treatment in patients in haemodialysis